Hello all, just registered on the forum today, lots of good info here.
Anyhow, I have a 2004 Disco S7, this morning my drivers window decided to stop working. All the other windows go up and down no problem, but when I hit the switch for the drivers window nothing happens. It worked fine yesterday, it was cold this morning, 28 degrees, not sure if that did something. I'm guessing the regulator went bad all of the sudden? It is the window that gets used the most.

 

Had the same here and went ahead and ordered the new motor and regulator before popping the door as it is a common issue based on searching the threads. Popped the door and low and behold it was nothing more than a roller being off track, which caused the window not to operate properly.
I'd pop the door and check to see what the issue is, and make sure to cut the plastic in a way in which you can put it back and reseal it using tape. Don't make my rookie mistake of putting the horse before the cart.

 

Mine would only go up. Crossed the wire in the door panel, would only go down. -> Grounded wire below dash. Replaced wires. 0$

Franky

 

Well, just popped off the door panel and had a look inside. One of the white plastic rollers was broken, so I guess that means I need a new regulator.

 

check out falcon works online for a fix that will last a lifetime as those damn rollers are cheap and will break again. If not you'll probable have to buy a new regulator fix it and be back in it again before you part with your truck.